a. Field of the Invention
The present invention relates to a total heat energy exchanger element which prevents odor transfer and the method of manufacturing same, wherein adsorbent particles are rigidly fixed to a sheet, such as metal, plastics, ceramic fiber paper and the like, and the sheet is laminated and formed into a honeycomb structure.
b. Description of the Prior Art
In U.S. Pat. No. 4,769,053, there is disclosed a method of producing a total heat energy exchanger material by attaching a composition comprising a molecular sieve to the surface of a sheet, the molecular sieve having a plurality of pores of a diameter of about 3 .ANG..
Examples of adsorbents used in the above-mentioned patent are zeolite and synthesized zeolite. Among moisture adsorbents, silica gel provides for high efficiency of total heat energy exchange and can be obtained easily. Silica gels used as adsorbents include A-type, B-type, RD-type, ID-type -and the like. A-type gel and RD-type gel, with large surface areas and small capacities of minute pores, have high efficiency of moisture adsorption in low humidity, but they have low efficiency of moisture adsorption in highly humid atmosphere. On the other hand, B-type and ID-type gels, with small surface areas and large capacities of minute pores, have high efficiency of moisture adsorption in highly humid atmosphere, but have low efficiency of moisture adsorption in conditions of low humidity (see the Handbook of Chemistry edited by The Chemical Society of Japan, Applied Chemistry Parts, Part 1, Process Section, Maruzen, pp. 256-257, Oct. 15, 1986), incorporated herein by specific reference. FIG. 1 illustrates equilibrium isotherms for water vapor adsorption of A-type, RD-type and B-type silica gels manufactured by Fuji Davison Chemistry Co., Ltd., zeolite and an active alumina at 25.degree. C. (see Technical Data 90072084 of this company, incorporated herein by specific reference). In this literature and others the type of silica gel as a moisture adsorbent is not specified. But in order to cope with hot and humid outer air during summer in Japan, B-type silica gel with high desiccative capacity in high humidity is generally used for multi-cylinder type dehumidifiers and for pressure swing adsorption type dehumidifiers.
But the silica gels mentioned above adsorb not only humidity but also various odors (gases). For example, in the summertime, hot and humid outer air is passed through a supply air zone of a rotating total heat energy exchanger element while return air from the room controlled at proper temperature and humidity is passed through a return air zone of the total heat energy exchanger element. Thus, by the rotating total heat energy exchanger element the temperature and the humidity of the outer air are lowered, and the resulting air is supplied in the room. In such an operation in the low humidity atmosphere, various odorous materials mixed in room air or outer air are adsorbed and accumulated on part of the silica gel particles in the total heat energy exchanger element.
In general, silica gel of any one of A-type, RD-type, ID-type and B-type has the characteristic of adsorbing humidity in preference to odorous materials. In the case of B-type silica gel, especially when highly humid outer air passes through an operating total heat energy exchanger element, such as in a rainy season or during a shower when the relative humidity of the air suddenly increases, the above-mentioned odorous materials adsorbed to and accumulated on the rotating element are suddenly purged by the adsorption of humidity contained in the outer air and these purged odorous materials are mixed into the supply air and distributed in the building causing the generation of odors in the rooms thereof, which odors are sensed by the occupants.